The U.S. Supreme Court opened its new term Oct. 5, 2026, with arguments over whether Boulder, Colorado, can pursue a lawsuit seeking to make ExxonMobil and Suncor Energy pay for climate-related costs facing the community. Boulder County filed the suit in 2018, alleging the companies and an industry trade group knew for decades that fossil fuels would contribute to climate change but misled the public about the risks. The county says it is seeking compensation for expenses including repairs, emergency services and property damage—not authority to regulate greenhouse gas emissions. The case remains in its early stages and has not gone to trial. Colorado’s Supreme Court allowed it to proceed, but the energy companies have asked the U.S. Supreme Court to intervene and dismiss it. They argue that climate change is a national and global issue that should be addressed by the federal government, not through state lawsuits. The legal fight is unfolding in a community still rebuilding from the Marshall Fire, which tore through Superior, Louisville and unincorporated Boulder County on Dec. 30, 2021, destroying more than 1,100 homes. Residents who lost their homes have described years of rebuilding and recovery. The county’s case also points to costs associated with heat, drought, flooding and wildfires, though the lawsuit’s allegations have not been tested at trial. Boulder says it is seeking compensation for local impacts, while the companies warn that allowing the case to proceed could expose businesses to claims across the country and effectively let states influence energy production elsewhere. The Trump administration has backed the companies, arguing that climate policy is a global matter. The ruling could affect dozens of lawsuits brought by states and municipalities against fossil-fuel companies. It may also carry implications for other cases involving local consequences of conduct that crosses state lines, including litigation over pollution, opioids and data centers. The court will also consider whether it has authority to review the Suncor case at this stage, before the dispute has gone to trial in Colorado. If the justices reach a 4-4 tie, the Colorado Supreme Court’s decision allowing the lawsuit to continue would stand. Justice Samuel Alito will not participate, the court informed lawyers a week before arguments. The clerk’s notice gave no reason. Environmental groups and watchdog organizations had urged Alito to recuse himself, citing investments in Phillips 66 and ConocoPhillips. Consumer Watchdog’s Justin Kloczko said the step was appropriate, adding that the public should not have to question whether a justice’s investments could benefit from a ruling. ExxonMobil referred questions to its court filings. Suncor did not respond to a request for comment. The Supreme Court’s decision will determine whether Boulder can continue its case, not whether the companies are liable for the damage the county describes.